Cordless Fluid Pump

ABSTRACT

A fluid pump having a housing with a fluid input and a fluid output, a removable power tool battery pack disposed within the housing, a motor disposed within the housing and electrically connected to the power tool battery pack, and an impeller driven by the motor for drawing fluid through an input opening and into an output opening. The fluid pump may be partially buoyant when placed in a fluid.

BACKGROUND

It is well known to provide a fluid pump that has a housing with a fluid input and a fluid output, a motor within the housing, and an impeller driven by the motor for drawing fluid, such as water, through the fluid input and into the fluid output. There are battery-powered fluid pumps that have an on-board non-removable rechargeable battery, or use multiple standard dry cells, such as D batteries.

SUMMARY

A fluid pump having a housing with a fluid input and a fluid output, a removable power tool battery pack disposed within the housing, a motor disposed within the housing and electrically connected to the power tool battery pack, and an impeller driven by the motor for drawing fluid through an input opening and into an output opening. The fluid pump may be partially buoyant when placed in a fluid.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a perspective view of a fluid pump.

FIG. 2 is a cross-sectional view of the fluid pump shown in FIG. 1 along plane II-II-II-II.

FIG. 3 is a partial cross-sectional view of the impeller assembly shown in FIG. 2 along line III-III.

DETAILED DESCRIPTION

Referring to FIGS. 1-3, a fluid pump 100 comprises a housing 11. Housing 11 is preferably made of a rigid material, such as plastic and in particular ABS, and has a bottom wall 11W to support the fluid pump 100 on the ground or support surface. Resilient, impact-absorbing material, such as elastomer or rubber, may be disposed on housing 11 in an overmolding process.

Housing 11 may have a handle 11H for carrying fluid pump 100.

Housing 11 may have a lid 11L. Preferably lid 11L is hingedly attached to housing 11. Lid 11L may be latched closed unto housing 11 via at least one latch (and preferably 3 latches) 11LL. Preferably the latch(es) 11LL has an overcenter mechanism and a hook lip 11LLH that catches a groove 11LG on lid 11L. Persons skilled in the art will recognize that latch(es) 11LL and groove 11LG may be provided instead on lid 11L and housing 11, respectively.

Preferably housing 11 and/or lid 11L carries at least one O-ring 11LO for sealing the space between housing 11 and lid 11L. Persons skilled in the art will recognize that, when lid 11L is latched shut via latch(es) 11LL, the O-ring 11LO is preferably compressed, creating a seal between housing 11 and lid 11L. Such arrangement ensures that fluid cannot enter the cavity 11C existing within housing 11 and lid 11L.

Housing 11 may also have rings 11R to latch on a strap (not shown) thereto in order to facilitate carrying fluid pump 100.

Housing 11 may also have electric terminals 11T disposed within cavity 11C. Such terminals 11T may electrically contact a power tool battery pack 30. Persons skilled in the art are referred to U.S. Pat. No. 8,653,787, which is incorporated herein by reference, for further information on power tool battery pack 35.

Power tool battery pack 35 may be electrically connected to a motor 21 disposed within housing 11. Motor 21 may be turned on and off via a switch 31 disposed on housing 11. Motor 21 may have a controller 21C for controlling speed and/or operation of motor 21.

Motor 21 preferably drives an impeller 22 with vanes 22V disposed within housing 11 to create a centrifugal pump for pumping fluid, such as water, etc. Persons skilled in the art will recognize that the appropriate impeller 22 can be selected for the desired application.

Impeller 22 preferably draws fluid through an input opening 23I, which may be disposed on the bottom wall 11W. Input opening 23I may have threads 23IT allowing the user to threadingly connect a suction hose (not shown).

A screen 23S may be disposed within input opening 23I to filter any solid bodies carried by the drawn fluid. Preferably screen 23S is removable for cleaning. Screen 23S may be disposed on a threaded ring that is engageable to threads 23IT, and is thus removable by rotating the threaded ring (and thus screen 23S).

As impeller 22 rotates (and thus vanes 22V) rotate, the fluid will be moved towards output opening 230. Preferably the output opening 230 has an outer wall 230W defining the output opening 230. Threads 230T may be disposed on outer wall 230W, enabling a user to threadingly engage a standard garden house to outer wall 230W.

Persons skilled in the art will recognize that the above arrangement discloses a centrifugal pump. Alternatively a positive displacement pump or a hybrid centrifugal/positive displacement pump could be used instead.

It is desirable to ensure that the motor 21 is not damaged by dry operation, i.e., where no fluid is being drawn via input opening 23I. This can be accomplished by turning on the motor 21 for a predetermined period of time and measuring the current flowing through motor 21. Such current measurement may be conducted by motor controller 21C.

If the motor current is below a predetermined current threshold, such as 3 amps, motor controller 21C may turn off motor 21 for a predetermined period of time. Preferably the period of time in which motor 21 is turned off will be longer than the period of time in which motor 21 is turned on.

If the motor current is higher than the predetermined current threshold, motor controller 21C may turn on motor 21 until the motor current falls below another predetermined current threshold, such as 4 amps.

It is desirable to provide a method for detecting a jammed impeller 22. During operation of fluid pump 100, motor controller 21C preferably monitors the torque of motor 21, so that a binding or jammed condition is detected when the motor torque rises at higher than a predetermined rate (dT/dt) and/or a predetermined threshold. Torque can be measured by motor controller 21C by monitoring motor current.

Once the binding or jammed condition is detected, the motor 21 can be momentarily stopped. Motor controller 21C can then provide short bursts of power to motor 21 so that to dislodge an object causing the bound/jammed condition. Alternatively, motor controller 21C can reverse the rotational direction of motor 21 in an attempt to dislodge an object causing the bound/jammed condition. Motor controller 21C can also light up an LED 34 to indicate a bound/jammed condition.

After attempting such corrective measures for a predetermined period of time, motor controller 21C can provide power to motor 21 for normal operation and continue monitoring motor current to determine whether the bound/jammed condition has been corrected. If the bound/jammed condition has not been corrected, motor controller 21C can turn off motor 21 and/or indicate the bound/jammed condition via LED 34.

Similarly, it may be desirable to provide a reverse flow switch 35 on housing 11. When such switch 35 is activated, motor control 21 can reverse the rotational direction of motor 21. Such reverse flow may provide a back flush of screen 23S. Persons skilled in the art will recognize that such back flush operation as presently described is user-initiated. However motor control 21 may be programmed to conduct such back flush operation after a predetermined condition has been met. Such predetermined condition may include length of motor on-time periods, number of motor on-time periods, etc.

It may desirable to provide a speed selector to enable the user to select a desired motor speed. Accordingly, a speed selector 32 may be disposed on housing 11. Speed selector 32 may be a rotary potentiometer so that the user can just rotate a knob connected to speed selector 32 to choose the desired motor speed. Motor controller 21C may receive a signal from speed selector 32 and control motor speed to match the desired user-selected speed.

It may be desirable to provide an operational mode where the fluid pump 100 pumps a specific volume of fluid at a time. A volume selector 33 may be disposed on housing 11. Volume selector 33 may be a rotary potentiometer so that the user can just rotate a knob connected to volume selector 33 to select the desired fluid volume to be pumped. Motor controller 21C may receive a signal from volume selector 33 and control motor speed and on-time to pump out the desired volume. Motor controller 21C may vary the motor speed and on-time based on the sensed motor current and motor voltage to compensate for head pressure losses, fluid viscosity, etc.

A user may desire to operate fluid pump 100 remotely. Preferably a wireless receiver 21W is disposed within housing 11. Wireless receiver 21W may be connected to an antenna 21WA.

The wireless receiver 21W may wirelessly receive a command from a remote control 21RC. Wireless receiver 21W may be connected to motor controller 21C to carry out the requested command.

Persons skilled in the art will recognize that such wireless transmission may occur via a radio frequency signal, such as, Bluetooth, Zigbee, cellular, WiFi, etc., or an infrared signal. Alternatively remote control 21RC may be connected to fluid pump 100 via a cable.

Remote control 21RC may enable the user to control some (or all) of the operational features of the fluid pump 100, such as on/off control, motor speed, rotational motor direction, back flush operation, fluid volume to be pumped out, etc. Remote control 21RC may have a display 21RD to show different operating parameters, such as remaining battery charge, motor speed, rotational motor direction, etc. Persons skilled in the art will recognize that, in order to provide information to be displayed, wireless receiver 21W is preferably a transceiver that can both transmit and receive information to and from remote control 21RC.

Persons skilled in the art will recognize that, instead of having a dedicated control unit such as remote control 21RC, such remote control functionality may be implemented in an application on a computer, tablet or smartphone. Persons skilled in the art will recognize by a single remote control 21RC (and/or its implementation on a computer, tablet or smartphone) may control more than one fluid pump 100.

Persons skilled in the art will recognize that having a cavity 11C increases the buoyancy of fluid pump 100. Housing 11 (and cavity 11C) may be designed so that fluid pump 100 is substantially buoyant when disposed on a fluid, such as water, even when a power tool battery pack 30 is disposed within cavity 11C. Preferably housing 11 (and cavity 11C) may be designed so that fluid pump 100 is substantially buoyant in an upright orientation so that input opening 23I is disposed within the fluid to be pumped. With such arrangement, the fluid pump 100 will not sink to the bottom of a flooded area and draw sediment through impeller 22.

The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the scope of the invention. 

What is claimed is: 1: A fluid pump comprising: a housing with a fluid input and a fluid output, a removable power tool battery pack disposed within the housing, a motor disposed within the housing and electrically connected to the power tool battery pack, and an impeller driven by the motor for drawing fluid through an input opening and into an output opening, wherein the fluid pump is partially buoyant when placed in a fluid. 2: The fluid pump of claim 1, wherein the housing has a cavity. 3: The fluid pump of claim 2, wherein the power tool battery pack is disposable within the cavity. 4: The fluid pump of claim 2, wherein the housing further comprises a lid. 5: The fluid pump of claim 4, wherein the lid defines a limit of the cavity. 6: The fluid pump of claim 1, wherein the housing may support a removable screen disposed by the fluid input. 7: The fluid pump of claim 1, further comprising a motor controller connected to the motor for controlling the motor. 8: The fluid pump of claim 7, further comprising a current sensor connected to the motor for measuring motor current. 9: The fluid pump of claim 8, wherein the current sensor provides motor current data to the motor controller. 10: The fluid pump of claim 9, wherein the motor controller turns off the motor if the motor current is below a predetermined threshold. 11: The fluid pump of claim 9, wherein the motor controller turns on the motor if the motor current is above a predetermined threshold. 12: The fluid pump of claim 9, wherein the motor controller calculates motor torque from the motor current data. 13: The fluid pump of claim 12, wherein the motor controller turns off the motor if at least one of the motor torque or a derivative of the motor torque current is higher than a predetermined threshold. 14: The fluid pump of claim 7, further comprising a reverse flow switch connected to the motor controller. 15: The fluid pump of claim 14, wherein the motor controller reverses motor direction if the reverse flow switch is activated. 16: The fluid pump of claim 7, further comprising a speed selector connected to the motor controller. 17: The fluid pump of claim 16, wherein the motor controller controls motor speed according to the input from the speed selector. 18: The fluid pump of claim 7, further comprising a wireless receiver connected to the motor controller. 19: The fluid pump of claim 18, wherein the motor controller controls the motor according to data received from the wireless receiver. 20: The fluid pump of claim 18, wherein the wireless receiver may receive data from at least one of a remote control, a computer, a tablet and a smartphone. 